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Why Is There No Effective Test for Ovarian Cancer?

08/26/2013 12:04 EDT | Updated 10/26/2013 05:12 EDT

Almost 20 years ago, I sat with 1,000 others at a fundraiser for a women's health organization to hear an elegant woman, Corinne Boyer, describe her medical roller-coaster ride which ended in a diagnosis of Stage Four ovarian cancer.

Ms. Boyer, who died from the disease shortly thereafter, made the point that awareness isn't the only key to paying attention to our health. Acting on what we know, and on what our instincts tell us, counts too. Even when her doctors pronounced that nothing was wrong, she pressed for further investigations. "Don't be passive. Listen to your body," she told the audience, adding that persistence is virtue and hoping that her story would help other women to be proactive in getting themselves checked out.

When a vibrant and lovely former colleague of mine died this weekend of an ovarian cancer that also was found too late, I realized how far we still have to go in getting a handle on this horrid disease which spreads by seeding itself, shedding malignant cells into the abdominal cavity. Unlike in breast and other cancers, we still don't have an effective screening system to spot this dangerous cancer in its early stages. Survival rates are not high because by the time this cancer is usually detected it is in an advanced state.

Ovarian cancer, called the disease that whispers because it typically causes no specific symptoms, is in desperate need of an early detection system. Despite Ms. Boyer's wise words, this is a disease that often presents no symptoms and is difficult to diagnose. As one oncologist told me, "These are often well women and then, boom, they run into a wall."

Today the American Cancer Society's online journal Cancer describes a study that, if verified in an ongoing clinical trial, could potentially help save the lives of thousands of us. In the study found here at Dr. Karen Lu of Texas' MD Anderson Cancer Center in Houston, tested the potential of a two-stage ovarian cancer screening strategy that incorporates changes in CA-125, a blood protein and a known tumor marker.

Dr. Lu told EurekaAlert! a science news organization, that the 11 year-study tested 4,051 post-menopausal women with an annual CA-125 blood test. Based on a risk analysis model known as the Risk of Ovarian Cancer Algorithm, women were then divided into three groups: Those who should receive another CA-125 blood test one year later (low risk), those who should have a repeat blood test in three months (intermediate risk), and those who should receive a transvaginal ultrasound and be referred to a gynecologic oncologist (high risk.)

"The results from our study are not practice-changing at this time," said Dr. Lu, but she added that such a screening strategy may eventually be beneficial in post-menopausal women with an average risk of developing ovarian cancer. She and her colleagues await results of a larger, randomized study currently being conducted in Britain, the results of which could mean we may finally have a screening strategy.

If and when we do, we may be able to find this lethal cancer in its early stages so that women can be treated and become well again.

Last week I also received an e-letter in which Dr. Barbara Vanderhyden addressed the same underlying question: Are we any closer to an early detection test for ovarian cancer?

The senior scientist at the Ottawa Hospital Research Institute who also leads an ovarian cancer research program says that the incidence of ovarian cancer in women is a lifetime risk of one in 70. Those at higher risk usually have a family history and they are the ones who benefit most from screening through a blood test for CA-125, ultrasound and possible prophylactic risk-reducing surgery.

Dr. Vanderhyden reports that researchers have recently discovered several new mutations in the BRCA1 and BRCA2 genes that we know can increase the risk of breast and ovarian cancers; in fact some reports indicate that mutations now account for almost 25 percent of all ovarian cancers.

Research has now yielded lots of evidence to suggest that many ovarian cancers seem to come from the fallopian tube. "It is anticipated that, by removing the fallopian tubes during hysterectomies performed for any reason, the incidence of ovarian cancer will be reduced," she writes. "This is not screening, but actual prevention."

In her view, while a lot of work has gone into the search for biomarkers that indicate the presence of ovarian cancer, so far none "have been proven to be sufficiently specific and sensitive to be clinically useful." That includes markers such as the CA-125 and new research into higher levels of serum calcium which are thought to be associated with an increased risk of ovarian cancer.

Dr. Vanderhyden thinks that to be able to identify women who are at higher risk is "a superb way to get those women into screening programs that will help them." (But it sounds like screening programs in Canada, for all women -- not just those identified as high risk -- may be a long way off.) Screening programs are not necessarily the be-all-and-end-all, concludes Dr. Vanderhyden. Maybe not, but surely we can do better than what we have now!

The same day that e-letter arrived, I noted an excellent slide show on ovarian cancer -- what it is and how it develops. Watch it now.

The annual fundraiser for ovarian cancer is coming up in your Canadian city: Sign up.

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